EP1883832B1 - Reception coil maintaining element for an mr-imaging system - Google Patents

Abstract

A reception coil maintaining element for an MR-imaging system includes two phase-controlled multi-element arrays of an RF multi-channel surface reception coil. Both of these phase-controlled, multi-element arrays have a reception surface including a center having a longitudinal axis that crosses that center. Each of these multi-element arrays is arranged on an arm which can pivot about a common pivotable axis. A vertical first plane is parallel to this pivotable axis. A vertical left plane extends along the longitudinal axis of the center of the left reception surface of the left multi-element array. A vertical right plane extends along a longitudinal axis of the center of the right reception surface of the right multi-element array. Both of these vertical left and right planes have approximately the same spacing with respect to the vertical first plane of the pivotable axis where the reception coil maintaining element in accordance with the present invention is in its operational state.

Description

The invention relates to a receiving coil holder for an MR imaging system according to the preamble of patent claim 1.

Mounts for the interest here for MR surface receiving coils have become well known, for example by the US Pat. No. 6,650,926 B1 ,
The US Pat. No. 6,650,926 B1 FIG. 12 shows a receive coil mount for single-housing, multi-element (coil) arrays of an RF multichannel surface receive coil system. This RF multichannel surface-receiving coil system enables a parallel imaging method for an MR imaging system of an MR tomograph having an operating main magnetic field direction given by its main magnet. The multi-element (coil) arrays each have a receiving surface, each with a center, each having a longitudinal axis passing through them.

It is well known that receiving coils designed as surface coils have a much smaller geometry than those which are body coils designed as receiving coils. Their disadvantage is their limited field of view (= FOV). Surface coils are therefore particularly suitable for medical diagnosis of certain small regions on the surface and inside the body and / or its extremities. However, using the parallel imaging technique using arrays of multiple coils to receive an MR signal, they produce high resolution images with high detection speed at high imaging speeds.

The invention has for its object a support for at least two mutually spaced, in the parallel imaging method (parallel imaging) working multi-element surface receiving coils to create, which allows optimization of the parallel imaging method (parallel imaging).

This object is solved by the features of claim 1.

The advantages of the invention are in particular that the arranged in two spatially separated, preferably in the same housings, in the parallel imaging method (so-called. "Parallel Imaging") working multi-element surface receiving coils together, or synchronously, directly or indirectly supported eg on a base plate, can be changed in their spatial position. Ideal Orientation The two multi-element surface receiving coils can be aligned (moved towards each other) so that the two receiving surfaces (field-of-view) of the two multi-element surface receiving coils mutually with their maximum shadow , z. B. by irradiation by polarized light cover. These Adjustment can, with the appropriate equipment, be maintained even if both multi-element surface receiving coils are moved synchronously in the same direction in space.
In a change in the distance between the two multi-element surface receiving coils to each other, it can be ensured that the two receiving surfaces (field-of-view) of the two multi-element surface receiving coils overlap each other at least with their partial shadows. From such a mutual "partial shade overlap" position can / can then by manual and / or motorized actuation ever an adjustment device - which is each connected, for example, positively or materially connected to the housings of the multi-element surface receiving coils - a and / or both multi-element surface receiving coils are moved (individually or jointly) in space so that they each lie in their mutual, currently as far as possible achievable shadow, or the momentarily largest possible image signal is generated.
The multi-element surface receiving coils can be advantageously accommodated in plastic housings attached to single plastic retainers. The overall brackets 6 and the individual brackets 24, 26, 22, 19, 23, 27 and 37, 34, 31, 36, 38, 39 can be designed in a variety of ways. For example, they can be straight or curved leaf springs or, for example, also flexible flexible arms made of MR-compatible material. Such designed holders make it possible to attach the housing with the multi-element surface receiving coils directly to the body parts to be examined, ie they are based indirectly on the base plate.
A quick manual, eg to reproduce a previous position, adjustment of the multi-element surface receiving coils, or their housings, is achieved, for example, by attaching scales to the joints with which the housings respectively on one arm or single bracket 24, 26, 22, 19, 23 27; 37, 34, 31, 36, 38, 39 are attached.
By means of the receiver coil total holder 6 or individual holders 24, 26, 22, 19, 23, 27; 37, 34, 31, 36, 38, 39 and their arrangement on / in a patient support, the number of necessary different configurations of surface coils for various examinations can be significantly reduced. Such difficult parts of the body, such as parts of the head, shoulder, neck, prostate, body joints can be examined using the receiver coil mounts according to the invention. In addition, the multi-receive coil array can each be placed extremely close to the body of the examiner, for example, without having to touch the body.
Also, the housings with the multi-element surface receiving coils can be easily replaced.
The receiver coil total holder according to the invention and / or the individual holders can be set up so that they allow only movements which make sense in accordance with the actual magnet main field direction of the gradient coil arrangement, horizontal or vertical main magnetic field MH. In the exemplary embodiment, the receiving coil holders are intended for a horizontally oriented magnetic main field direction MH of an MR tomograph.

An embodiment of the invention is illustrated by drawings and will be described in more detail below:

• Figur 1 eine Empfangsspulen-Gesamt-Halterung mit zwei Einzel- Halterungen für ein MR-Bildgebungssystem mit zwei Gehäusen mit Mehr-Element- Oberflächen-Empfangsspulen, die in Hauptmagnetfeldrichtung MH des Hauptmagnetfeldgerätes eines MR-Tomographen ausgerichtet sind, wobei die Empfangsspulen-Gesamt-Halterung um 90° um ihre horizontalen Längsachse gedreht ist,
• Figur 2 die Empfangsspulen-Gesamt-Halterung für ein MR- Bildgebungssystem nach Figur 1, mit einer entlang der Hauptmagnetfeldrichtung MH in das Innere des MR- Tomographen einbringbaren Grundplatte, an der die Empfangsspulen-Halterungen befestigt sind.

Show it:

• FIG. 1 a total receive coil mount comprising two single mounts for a dual housing MR imaging system having multi-element surface receive coils aligned in main magnetic field direction MH of the MR main magnetic field device, the receive coil total mount being 90 ° apart ° is rotated about its horizontal longitudinal axis,
• FIG. 2 the receiver coil total mount for an MRI system FIG. 1 with a base plate, which can be introduced into the interior of the MR tomograph along the main magnetic field direction MH, to which the receiving coil holders are fastened.

All parts of the receiving coil mounts, housing and base are made of MR compatible material.
On a base plate 1 are regularly distributed over its upper surface 2, a plurality of fastening means 3 for the feet 4 of a receiving coil-total holder 6 is provided. These fasteners 3 may be performed, for example, as Gleitfeder- connections. For this purpose, a plurality of identical vertical holes 7, each with a vertical spring groove 8 in the base plate 1 are provided.
The foot 4 has, for example, at its lower part 11, a cylindrical pin 12 whose diameter is matched to the bore 7 on sliding seat. In addition, the cylinder pin 12 has a matched to the spring groove 8 of the bore 7 flat spring 13. The diameter of the foot 4 is greater than the diameter of the holes 7. The inserted into holes 7 foot 4 is arranged rotationally. The majority of holes 7 in the base plate 1 serves to provide choices through the holes 7, which serve as "support points" 7 as close as possible to examine part of the body to the two multi-element surface receiving coils, left 14 right 16, with their respective To bring housings 17, 18 at an adjustable distance to be examined part of the body.

With a left-angled arm 19, preferably with its end, the left housing 17 is positively connected by means of a left joint 21. The joint 21 may be a joint with two degrees of freedom or three degrees of freedom. So it may be, for example, a lockable universal joint or a lockable ball joint.
The left hinge 21 serves as the left housing 17 and thus the arranged within it, for example, the first (phased) 4-element coil array RF 8-channel surface coil as well as possible to the contour of a first side of the part to be examined of the body is approximated.

The left arm 19 is embodied, for example, as a one-armed angle lever with a first leg 22 and with a second leg 23 that is materially connected to it, for example. The angle α, which may include the two legs 22 and 23, may be in the range of acute to obtuse, for example 120 °.
The end 24 of the left arm 19 coincides with the beginning 26 of the first leg 22. The beginning 27 of the left arm 19 coincides with the beginning 28 of the second leg 23. The beginning 27 of the left arm 19 has a bearing bore and is designed on a short horizontal distance, for example 25 mm, as a cross-section-reduced tongue with a bearing bore. At a distance a of eg 60 mm from the center of the bearing bore is with an outer surface 28 of the second leg 23, a left web 29, which has a left-hand threaded hole, for example, materially connected.
The parts 24, 26, 22, 19, 23, 27 form a left individual mount for the left housing 17.

With a right angled arm 31, preferably with its end, by means of a left joint 32, the right housing 18 is positively connected. The joint 32 may be a joint with two degrees of freedom or three degrees of freedom. It may for example be a lockable universal joint or a lockable ball joint.
The hinge 32 serves as the right housing 18 and thus the disposed within him eg second (phased) 4-element coil array of the RF 8-channel surface coil as well as possible to the contour of the other side of the examined part of the Body is approximated.
The right arm 31 is embodied, for example, as a one-armed angle lever with a first right leg 34 and with a second right leg 36 connected to it in a materially bonded manner, for example. The angle = α, which may include the two legs 34 and 36 are in the range of acute to obtuse, eg 120 °.
The end 37 of the right arm 31 coincides with the beginning 37 of the first right leg 34. The beginning 38 of the right arm 31 coincides with the beginning 39 of the second, right leg 36. The beginning 38 of the right arm 31 has on a short horizontal distance, for example 25mm, two spaced, horizontal provided with a bearing bore webs. At a distance a of eg 60mm from the center of the bearing bore is with an outer surface 41 of the second leg 36 is a right web 40, which has a right-hand threaded hole, for example, materially connected.
The parts 37,34,31,36,36,39 form a right single holder for the right housing 18th

The beginning 27 of the left arm 19 and the beginning of the right arm 31 are pivotally mounted on their bearing bores on eg in a pivot joint with the degree of freedom f = 1, for example on a split pin 42 (pivot center) of a fork joint 43 with the degree of freedom f = 1.
In the embodiment, the beginning 27 of the left arm 19 comes to lie in the form of a tongue between the two spaced, horizontal, each with a bearing hole provided webs of the beginning 38 of the right arm 31. All three bearing bores are threaded together on the cotter pin of the rotary joint 43.
To generate a preferably synchronous pivoting movement about the pivot center 42 of the joint 43, a manual or motor drive 44 is provided.
In its simplest form, it consists of a threaded spindle mounted and hardened in the interior of the joint 43. It has a left threaded piece and a right threaded piece. For example, at the outer end of the left threaded piece drives a drive.
The external left-hand thread of the left-hand threaded part of the threaded spindle engages with an internal left-hand thread through a ball of a left-hand ball joint. The ball joint is attached, for example, at the end of a left carriage, which is movable in a longitudinally oriented guide in the left web 29. Upon rotation of the threaded spindle 29, a pivoting movement of the left arm 19 is generated via the left web.
The right-hand thread of the right-hand threaded part of the threaded spindle engages with an inside-right thread through a ball of a right-hand ball joint. The ball joint is fastened, for example, at the end of a right carriage, which is movable in a longitudinally aligned guide in the right web 29. Upon rotation of the threaded spindle, a pivoting movement of the right arm 31 is effected via the right web 40.
To adjust the thickness setting to the body part to be examined, the distance of the first phased 4-element coil array of an RF 8-channel surface coil to the second phased 4-element coil array of an RF 8-channel surface coil be changed accordingly. This happens, for example, via a rotation of the threaded spindle. Depending on their direction of rotation of the threaded spindle, the two arms 19 and 31 about their common axis of rotation 42 synchronously to each other - or moved away from each other. The arms 19, 31 are followed by the housings 17 and 18 fixed to them with their first and second phased 4-element coil arrays of an RF 8-channel surface coil. Roughly a parallel image is preserved. The fine adjustment is done via adjustment of the housing 17 and 18th
In other words, the receiving coil mounts for an MR imaging system are configured to operate two multi-element (coil) arrays of an RF multi-channel surface receiving coil. Each of the two multi-element phased array (coil) arrays each has a receiving surface, each with a center, each having a longitudinal axis k1, k2 traversing it. Both multi-element (coil) arrays (14; 16) are each arranged on a movable arm 19, 31 or a single holder, for example, about a common pivot axis pivotable arm 19, 31. From the exemplary arrangement, it will be seen that a vertical left plane spanned along the longitudinal axis of the center of the left receiving surface of the left multi-element (coil) array 14 and one along the longitudinal axis of the center of the right receiving surface of the right multi-element (FIG. Spool) -Array 16 spanned vertical right-hand plane parallel and spaced from each other to a along the pivot axis 42 and 46 spanned, vertical, first plane. It follows that, depending on the (jointly) set working position of the multi-element (coil) array 14, the left-hand plane and the right-hand plane respectively have the same or approximately the same distance b from the first plane. The distance b of the left plane and the distance b of the right plane from the first plane is changeable, but both distances are always equal or approximately equal to each other, if a common, ie a synchronous movement of the left single holder 24, 26, 22, 19, 23 27 and the right single holder 37, 34, 31, 36, 38, 39 with their housings 17,14 and 18,16.

In some cases, a separate movement of the individual brackets is desired. This is also possible with the subject of this invention.

The joint 43 is tied off on a pin 46 of a second fork joint 47 with a degree of freedom f = 1 and rotatably mounted and fixable in each rotational position. Between the left web 48 and the right web 49 of the fork joint 47, a first end 52 of a rod 53 is mounted on a bolt 51 and pivotable about its axis of rotation and fixable. The axis of rotation of the bolt 51 is always aligned transversely (90 °) to the main magnetic field direction MH.
On top of the foot 4, another fork joint 54 is provided with degree of freedom f = 1 rotationally. Between the left web 56 and the right web 57 of the fork joint 54, a second end 57 of the rod 53 is mounted pivotably and fixably on a bolt 56 and its axis of rotation. The axis of rotation of the bolt 56 is always aligned transversely (90 °) to the main magnetic field direction MH.

The arrangement of the two yokes 47 and 54, it is possible the entire receiver coil-total holder 6, - without that a transverse movement can take place to the main magnetic field direction MH- to move in and against the main magnetic field direction MH.

Instead of the rod 53 with the two yokes 47 and 54 for longitudinal movement of the receiver coil-total holder 6 and the individual holders 24, 26, 22, 19, 23 27 and 37, 34, 31, 36, 38, 39 on the base plate 1 are also other technical means that are flexible in one direction, rotationally fixed and lockable in any position, applicable, eg flexible arms.

A change in location of the receiving coil-total holder 6 or the individual holders, if desired, along the upper surface 2 of the base plate 1 is not only possible by means of fitting holes 7. This type of change of location of the receiver coil-total holder 6 and the individual holders 24, 26, 22, 19, 23 27 and 37, 34, 31, 36, 38, 39 is only a simple embodiment with eg a guide. Thus, for example, in or on the base plate 1 in-parallel or transverse to the main magnetic field direction MH to the upper surface 2 open towards sliding straight-line guides, eg be provided dovetailed guide grooves. In the guide grooves (fixed part of the guide) could be provided on the dovetail profile adapted slider (movable part of the guide) on which then the foot 4 for brackets 6 and 24, 26, 22, 19, 23 27 and 37, 34, 31, 36, 38, 39 could be attached. The slider would be easy to move and lock. So as a planar movement of the slider, ie the receiver coil total holder. 6
For example, the sliders could be selectively moved and / or locked by means of MR-compatible transmissions and motors (hydraulic motors), servo-cylinders, etc.
The overall holder 6 can also be attached to other location than on the base plate 1. For example, be attached directly or indirectly to the MR device.

In summary, it is intended to provide a receive coil mount for multi-element (coil) arrays of RF multi-channel surface receive coils surrounding a housing for facilitating parallel imaging for an MRI MR imaging system with one of its main magnets predetermined operating main magnetic field direction (MH) are created. The multi-element (coil) arrays each have a receiving surface, each with a center, each having a longitudinal axis k1, k2 traversing it. The housings 18, 17 with the multi-element (coil) array can by means of a joint 21 bzw.32 at the end 24 and 37 of the individual holders 24, 26, 22, 19, 23 27 and 37, 34, 31, 36, 38, 39 each one the housing 17 or 18) are attached.

The beginnings 27 and 39 of the individual holders 24, 26, 22, 19, 23, 27 and 37, 34, 31, 36, 38, 39 may be positively or materially connected.
It is a, provided in the interior of an MR scanner base plate 1 is provided. The base plate 1 has a number of fastening means 7 for the individual holders 24, 26, 22, 19, 23, 27 and 37, 34, 31, 36, 38, 39, respectively.
As fastening means 7, a number of straight guides and / or sliding spring connections can be provided.
Attached to the base plate 1 of the fixed part of the guide and / or Gleitfeder- connection. The fixed part of the straight guides and / or Gleitfeder- connection is in- and / or transversely or laterally aligned parallel to the intended operating main magnetic field direction (MH) of the main magnetic field of the intended MR tomograph. The beginnings 27,39 of the two individual brackets 24, 26, 22, 19, 23 27; 37, 34, 31, 36, 38, 39 can directly or indirectly with one or with a single common, movable part of the straight guide, eg the profile of the fixed guide adapted movable sliders or Gleitfeder- connections are connected. That is, the moving parts of the guide and Gleitfeder- connection and the fixed part of the guide are positively connected by means of sliding fit.
In a further embodiment, at least one of the two individual holders 24, 26, 22, 19, 23 27; 37, 34, 31, 36, 38, 39 attached directly or indirectly to a movable part 43 of a bearing 43, 46. The movable part 43 of the bearing 43, 46 is mounted rotatably on a bearing part 46 of the bearing 43, 46. In this case, the longitudinal axis of the supporting part 46 is forcibly aligned in and against the intended main operating magnetic field direction (MH) or in the horizontal direction parallel to it. The supporting part 46 is supported directly or indirectly on the base plate 1. Also, its vertical distance from the base plate 1 is adjustable.
Also, the distance of the housing 18,17 each other, seen transversely to the intended operating main magnetic field direction (MH), for example by moving the sliders (feet) with the form-fitting or cohesively connected to individual brackets.
The location of the housings 18, 17 with their multi-element (coil) array 14; 16 is seen in and opposite to the intended operating main magnetic field direction (MH), adjustable. For this example, the individual holders 24, 26, 22, 19, 23 27; 37, 34, 31, 36, 38, 39 have corresponding longitudinally aligned straight guides, at the movable and fixable parts of which the housings 18, 17 are connected via the joints 32, 21.
The joints 21; 32 are pivotable and lockable and have a degree of freedom f = 2 or f = 3.
The beginnings 27, 39 of the two single holders 24, 26, 22, 19, 23 27; 37, 34, 31, 36, 38, 39 are connected for example by means of a joint 42,43. Thus, the opening angle = α between the two individual holders 24, 26, 22, 19, 23 27; 37, 34, 31, 36, 38, 39 are set in an optional size.

LIST OF REFERENCE NUMBERS

1

baseplate

2

Surface, upper

3

fastening device

4

foot

5

-

6

Receiver coil holder

7

Bore, vertical

8th

Feather groove, vertical

-

-

10

-

11

Part, lower (4)

12

cylinder journal

13

flat spring

14

Multi-element surface receiving coil, right

15

-

16

Multi-element surface receiving coil, left

17

Housing, left

18

Housing, right

19

Arm, angled, left

20 -

21

Joint, left

22

Thighs, first

23

Thigh, second

24

End of 19

25

-

26

Beginning of 22

27

Beginning of 19

28

Outer surface of 23

29

Footbridge, left

30 -

31

Arm, angled, right

32

Joint, left

33

-

34

Thighs, first, right of 31

35

-

36

Thigh, second, right

37

End, right thigh (34)

38

Beginning, from 31

39

Beginning, from 36

40

Footbridge, right

41

Outer surface of 36

42

cotter

43

Fork joint, moving part

44

Drive for 19 and 31

45

-

46

spigot

47

Fork joint, second

48

Footbridge, left of 47

49

Footbridge, right of 47

50

-

51

Bolt of 47

52

End of 53

53

pole

54

Fork joint, first

55

-

56

Bolt of 54

57

End, second of 53

58

-

59

-

Claims (14)

1. A reception-coil holder for a multielement (coil) array, which is surrounded by a housing in each case, of an RF multichannel surface reception coil to permit parallel imaging for an MR imaging system of an MR tomograph with an operating main magnetic field direction (MH) determined by its main magnet, each coil of the phase-controlled multielement (coil) array having in each case a receiving face comprising a centre and comprising a longitudinal axis (k1, k2) passing through it, characterized in that
   a holder (24, 26, 22, 19, 23 27; 37, 34, 31, 36, 38, 39) which is separate from the array housings is provided per housing
   and in that said housing (18, 17) with the multielement (coil) array can be fixed at the end (24, 37) of one holder (24, 26, 22, 19, 23 27; 37, 34, 31, 36, 38, 39) in each case by means of a joint (21, 32).
2. Reception-coil holder according to claim 1, characterised in that the holders (24,26, 22, 19, 23 27; 37, 34, 31, 36, 38, 39) are designed as leaf springs.
3. Reception-coil holder according to claim 2, characterised in that the holders (24, 26, 22, 19, 23 27; 37, 34, 31, 36, 38, 39) are designed so as to be flexurally rigid or flexurally elastic or resiliently rigid.
4. Reception-coil holder according to claims 1 to 3, characterised in that the starts (27, 39) of the two holders (24, 26, 22, 19, 23 27; 37, 34, 31, 36, 38, 39) are interlockingly or integrally connected.
5. Reception-coil holder according to claims 1 to 4, characterised in that the starts (27, 39) of the two holders (24, 26, 22, 19, 23 27; 37, 34, 31, 36, 38, 39) are connected via a joint (42, 43).
6. Receiving-coil holder according to claims 1 to 5, characterised in that the assembled two holders (24, 26, 22, 19, 23 27; 37, 34, 31, 36, 38, 39) are designed as compression springs, the ends of which are opposite to the housings (18, 17), which are mounted on them.
7. Reception-coil holder according to claims 1 to 6, characterised in that a base plate (1), which can be introduced into the interior of an MR tomograph is provided and in that the base plate (1) has a number of fastening devices (7) for the holders (24, 26, 22, 19, 23, 27; 37, 34, 31, 36, 38, 39).
8. Reception-coil holder according to claims 1 to 7, characterised in that, as fastening devices (7), a number of straight guides and/or sliding key connections are provided.
9. Reception-coil holder according to claim 8, characterised in that the fixed portion of the guide and/or sliding key connection is provided on the base plate (1).
10. Reception-coil holder according to claims 1 to 9, characterised in that the fixed portion of the straight guides and/or sliding key connection are oriented in and/or transverse to or laterally parallel to the provided operating main magnetic field direction (MH) of the main magnetic field of the provided MR tomograph, and in that the starts (27, 39) of the two holders (24, 26, 22, 19, 23 27; 37, 34 31, 36, 38, 39) can be directly or indirectly connected with one in each case, or with a single, common movable portion of the straight guide or sliding key connection, and in that the movable portions of the guide and sliding key connection and the fixed portion of the guide with sliding seat are interlockingly connected.
11. Reception-coil holder according to claims 1 to 10, characterised in that at least one of the holders (24, 26, 22, 19, 23 27; 37, 34 31, 36, 38, 39) can be directly or indirectly fastened on a movable portion (43) of a bearing (43, 46), that the movable portion (43) of the bearing (43, 46) is arranged so as to be rotatable around a supporting portion (46) of the bearing (43, 46), that the longitudinal axis of the supporting portion (46) is positively oriented in and opposite to the operating main magnetic field direction (MH) or parallel thereto in a horizontal direction and the supporting part (46) is supported directly or indirectly on the base plate (1) and its vertical distance thereto is adjustable.
12. Reception-coil holder according to claim 1 to 11, characterised in that the distance between the housings (18, 17) with their multielement (coil) arrays (14; 16) is adjustable seen in and opposite to the provided operating main magnetic field direction (MH).
13. Reception-coil holder according to claim 1 to 12, characterised in that the position of the housings (18, 17) with their multielement (coil) arrays (14; 16) is adjustable seen in and opposite to the provided operating main magnetic field direction (MH).
14. Reception-coil holder according to claims 1 to 13, characterised in that the housings (17; 18), in the region of the end (24, 37) of their holders (24, 26, 22, 19, 23 27; 37, 34, 31, 36, 38, 39), are pivotably and arrestably arranged by means of a joint (21; 32) with the degrees of freedom 2 or 3.

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